1. Field of the Invention
The present invention relates to a carbon fine particle structure as a useful novel substance that is obtained by structuralizing an inexpensive carbon fine particle material, such as carbon black and graphite, a process for producing the same, a carbon fine particle transcriptional body for producing the same, and a solution for producing a carbon fine particle structure.
The invention also relates to a carbon fine particle structure electronic device and an integrated circuit having high usefulness using the carbon fine particle structure, and a process for producing the carbon fine particle structure electronic device.
2. Description of the Related Art
A carbon fine particle material, such as carbon black and graphite, has been used as a conductive paste, a pigment and a conductivity imparting agent for rubber and plastics. The carbon fine particle material is superior since it has corrosion resistance and heat resistance, which cannot be attained by a metallic material, can be used as a conductive material having good sliding property, and exerts a low environmental load with low cost. However, the particle diameter of the carbon fine particle material cannot be increased from the technical and cost conditions, and the material is limited in use as a dispersed material.
In the case where carbon fine particles can be chemically bonded to each other to form a conformation like a polymer, it is expected that the mechanical strength and the film forming property thereof can be improved, whereby the applications thereof are broadened to an electronic device part, such as an electrode, formed of the material solely, with the characteristics inherent to the carbon fine particles being exploited. Furthermore, there is another possibility that novel characteristics arise in electroconductivity or the like, for example, by selecting a crosslinking agent.
Along with the progress in information technology in recent years, development of a thin film transistor (TFT) used in a display and a communication equipment receives interest. Amorphous silicon and polysilicon have been currently used mainly as a semiconductor material for TFT. However, the production of the semiconductor device generally requires a vacuum process, such as sputtering, and a high temperature process. Accordingly, only a limited and high-cost material can be selected as a substrate, and therefore, the application of the semiconductor device obtained through the device production process using the substrate material is limited in cost and capability.
Such other requirements are also arising in TFT as flexibility and production on a large area. According thereto, an organic semiconductor (organic TFT) receives attention, in which a device can be produced (i) on a flexible substrate, such as plastics, (ii) on a large area (iii) by a low-cost process, such as printing.
Wide varieties of materials including from low molecular weight materials to high molecular weight materials have been reported as a material for the organic TFT, such as pentacene, phthalocyanine, fullerene and polythiophene, as disclosed in Advanced Material, vol. 2, p. 99 (2002) (review). However, the production process with low temperature and low cost and the high capability are conflicting demands, and it is difficult to attain both of them simultaneously.
For example, a material exerting high capability, such as pentacene, requires production by a vapor deposition process in high vacuum, which is not desired from the standpoint of obtaining a large area and attaining a low-cost production process. An organic semiconductor material, such as polymer compound, can be easily produced as the device with high productivity, but the sufficient capability cannot be obtained.
The most of the organic semiconductor materials are of p type, but there are fewer kinds of materials exhibiting the n type behavior, and moreover the stable operation thereof can be attained only in vacuum or in a nitrogen atmosphere.
Consequently, such a polymer organic semiconductor material has been demanded that attains high capability with the convenience in production process maintained.
JP-A-2003-292588, JP-A-2003-502874, Journal of Applied Physics, vol. 92, p. 5295 (2002) can be enumerated as such know document.